Reactor effects during propylene

Reactor Surface Effects During Propylene Pyrolysis... 

In 1973, Stallings reportedly ] the polymerization of vinylidene fluoride into a polymer suitable for coatings applications. The polymerization took place in the presence of beta-hydroxyethyl tertiary butyl peroxide (initiator), a lower alkylene oxide and a water-soluble fluorinated surfactant at 10.4 MPa or higher monomer pressure. Alkylene oxide (0.02-0.5% of the monomer weight) played a beneficial role in minimizing polymer build-up on the reactor walls during the run times of 0.5-6 hours. An effective lower alkylene oxide contained 8 carbons or less in its molecule, e.g., ethylene or propylene oxide. 

UOP and Norsk Hydro have jointly developed and demonstrated a new MTO process utilizing a SAPO-34 containing catalyst that provides up to 80% yield of ethylene and propylene at near-complete methanol conversion. Some of the key aspects of the work have included the selection of reactor design for the MTO process and determination of the effects of process conditions on product yield. Evaluation of the suitability of the MTO light olefin product as an olefin polymerization feedstock and demonstration of the stability of the MTO-lOO catalyst have also been determined during the development of this process. 

As mentioned in the introduction, the effect of attrition on the particle size distribution is quite often as relevant as the attrition-induced loss is. The reason is quite obvious it is the strong dependence of the process performance on the bed particle size distribution. In the chemical industry, for example, the content of fines, i.e., the mass of particles below 44 microns, has often been observed to have a strong effect on the fluidized bed reactor performance, de Vries et al. (1972) reported an increase in the conversion of gaseous hydrogen chloride in the Shell chlorine process from 91 to 95.7% with an increase of the fines content in the bed material from 7 to 20%. The same effect was observed by Pell and Jordan (1988) with respect to the propylene conversion during the synthesis of acrylonitrile. They reported on an increase of the conversion from 94.6 to 99.2% as the fines content was changed from 23 to 44%. 

---